samples/bpf/xdp1_user.c

   1 /* Copyright (c) 2016 PLUMgrid
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #include <linux/bpf.h>
   8 #include <assert.h>
   9 #include <errno.h>
  10 #include <signal.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15
  16 #include "bpf_load.h"
  17 #include "bpf_util.h"
  18 #include "libbpf.h"
  19
  20 static int ifindex;
  21
  22 static void int_exit(int sig)
  23 {
  24         set_link_xdp_fd(ifindex, -1);
  25         exit(0);
  26 }
  27
  28 /* simple per-protocol drop counter
  29  */
  30 static void poll_stats(int interval)
  31 {
  32         unsigned int nr_cpus = bpf_num_possible_cpus();
  33         const unsigned int nr_keys = 256;
  34         __u64 values[nr_cpus], prev[nr_keys][nr_cpus];
  35         __u32 key;
  36         int i;
  37
  38         memset(prev, 0, sizeof(prev));
  39
  40         while (1) {
  41                 sleep(interval);
  42
  43                 for (key = 0; key < nr_keys; key++) {
  44                         __u64 sum = 0;
  45
  46                         assert(bpf_map_lookup_elem(map_fd[0], &key, values) == 0);
  47                         for (i = 0; i < nr_cpus; i++)
  48                                 sum += (values[i] - prev[key][i]);
  49                         if (sum)
  50                                 printf("proto %u: %10llu pkt/s\n",
  51                                        key, sum / interval);
  52                         memcpy(prev[key], values, sizeof(values));
  53                 }
  54         }
  55 }
  56
  57 int main(int ac, char **argv)
  58 {
  59         char filename[256];
  60
  61         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  62
  63         if (ac != 2) {
  64                 printf("usage: %s IFINDEX\n", argv[0]);
  65                 return 1;
  66         }
  67
  68         ifindex = strtoul(argv[1], NULL, 0);
  69
  70         if (load_bpf_file(filename)) {
  71                 printf("%s", bpf_log_buf);
  72                 return 1;
  73         }
  74
  75         if (!prog_fd[0]) {
  76                 printf("load_bpf_file: %s\n", strerror(errno));
  77                 return 1;
  78         }
  79
  80         signal(SIGINT, int_exit);
  81
  82         if (set_link_xdp_fd(ifindex, prog_fd[0]) < 0) {
  83                 printf("link set xdp fd failed\n");
  84                 return 1;
  85         }
  86
  87         poll_stats(2);
  88
  89         return 0;
  90 }